code: def sphinx_clean(build_dir):
      if op.isdir(build_dir):
          shutil.rmtree(build_dir)
      os.mkdir(build_dir)
      print("Cleared build directory.")
  
file_path: imageio/tasks/docs.py
imports: import os
  import sys
  import os.path
  import shutil
  from invoke import task
  from ._config import DOC_DIR, DOC_BUILD_DIR
label_desc: Use image node_id 2 for calling a global function with example usage: sphinx_clean(build_dir) without return types